The present invention relates generally to a wheel assembly with an integrated suspension for use in a variety of all terrain and high speed applications with the integrated suspension being configured to allow the wheel assembly to move upwardly and rearwardly in response to an impact force. More specifically, the present invention relates to dolly wheels for use with a vehicle that provides maneuverability resulting in what is termed zero turn capability. The present invention also offers advantages when related to vehicle wheels, including both fixed position and steered.
Dolly wheels are commonly used on vehicles or other devices which operate at low speeds (0-10 m.p.h.) as well as on industrial trucks and dollies and other equipment where it is advantageous to have zero turn capabilities. The wheels on such dolly wheel suspensions are subjected to relatively high impact forces when they engage an obstruction. These impact forces typically increase as a function of increasing speed and weight or load and operation in rough surface engagement conditions.
Shock absorbing dolly wheel suspensions, which help reduce the transmission of impact forces from the ground engaging wheels to the vehicle load, or load supported thereby, currently exit. Many of these shock absorbing dolly wheel suspension systems utilize a variety of springs attached to different support members to minimize the effect of impact forces that are encountered by the dolly wheels on the vehicles. While these dolly wheel suspension systems provide satisfactory performance, they normally require a relatively large devoted envelope within which to locate the suspension within the vehicle. This large devoted envelope requires structuring the vehicle to accommodate the larger suspension, which thus increases the overall cost of the vehicle. There are also dolly wheel systems that use a short spring or elastomeric compression component to dampen impact loads. However, while compact in size, these systems are relatively limited in suspension travel and travel dampening characteristics that are generally accomplished with a shock absorber utilized within a larger system.
Further, suspension systems for vehicle wheels of the non-dolly wheel type have been developed with a variety of different configurations. These suspension systems are incorporated into a variety of different vehicles, including automobile, motorcycle and the like. Current suspension systems are typically configured such that they are located inwardly of the vehicle wheel and their components move generally along the axis of the wheel. Because these suspension systems are located inwardly of the vehicle wheel, they require a relatively large amount of space. These suspension systems provide satisfactory performance. However, the amount of space required to accommodate the suspension system is disadvantageous for many uses.
It would thus be advantageous to provide a dolly wheel suspension system that provides significant travel, and requires significantly less space without sacrificing performance. It would also be advantageous to provide a suspension system for a fixed location wheel or a wheel of steering capability that requires significantly less space without sacrificing performance.
It is therefore an object of the present invention to provide a wheel suspension system for a vehicle that will effectively absorb the shocks incident to travel of the vehicle over irregular road surfaces.
It is another object of the present invention to provide a dolly wheel suspension system in which the dolly wheel is mounted for generally up and down movements as it encounters irregularities in road surface and is arranged with a spring and shock absorber to yieldably resist upward movement of the wheel and to absorb road shocks resulting in the minimum upward component of movement of the vehicle itself.
It is yet another object of the present invention to provide a wheel suspension system that can be packaged in a much smaller area within a vehicle than prior suspension systems.
It is a related object of the present invention to provide a wheel suspension system that can be utilized with dolly wheels having zero turn capabilities.
It is still a further object of the present invention to provide a dolly wheel suspension system that includes the full shock absorption and spring action that is currently present in existing automotive vehicles.
It is still another object of the present invention to provide a suspension system for a fixed location wheel, a controlled steered wheel of a vehicle, or an unrestrained dolly wheel that is fully integrated within the rim of the wheel.
In accordance with the above and the other objects of the present invention, a wheel suspension system is provided. In the case of a dolly wheel, the suspension system includes a dolly wheel, a wheel carrier arm, and a dolly wheel spindle rotationally secured to a frame element of the vehicle. The dolly wheel spindle has a generally vertical axis of rotation and the wheel carrier arm and the dolly wheel rotate about the axis of rotation. The wheel carrier arm is rotatably secured to the dolly wheel spindle and acts as a swing arm for the dolly wheel. The wheel carrier arm has a first end that is pivotally secured to the dolly wheel spindle and extends downwardly from the pivot point defined by the connection of the wheel carrier arm to the dolly wheel spindle. The wheel carrier arm has a method for rotatably mounting the dolly wheel being generally located in its mid body. The wheel carrier arm has a second end that is remote from the first end with the second end being secured to a first end of a shock absorber. The wheel carrier arm is moveable about the pivot point thereby compressing or extending the shock absorber. The shock absorber incorporates a spring and is rotatably secured at a second end to an extending arm of the dolly wheel spindle. The dolly wheel has an outer periphery and the shock absorber is located within an area defined by the outer periphery of the dolly wheel to minimize the space needed for the suspension system.
Other objects and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.